<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

<div>
  <input type="text" v-model="n1">
  <input type="text" v-model="n2">
  <input type="button" value="加" @click="f('+')">
  <input type="button" value="减" @click="f('-')">
  <input type="button" value="乘" @click="f('*')">
  <input type="button" value="除" @click="f('/')">
  <h3>结果:{{result}}</h3>
</div>

<script src="js/vue.min.js"></script>
<script>
  let v= new Vue({
    el:"body>div",
      data:{
        n1:"",
          n2:"",
          result:""
      },
      methods:{
        f(x){
            //eval()方法key将字符串以js代码的形式运行，将运行结构返回
            v.result = eval(v.n1+x+v.n2);
        }
      }

  })
</script>
</body>
</html>